This invention relates to imaging and particularly to imaging using the imagewise control of an intense radio-frequency field to change the physical characteristics of a material. The change in physical characteristics, for example, color, texture or phase, provides an image.
It is known that data recording can be obtained with a film of amorphous hydrogenated silicon or germanium, making use of the fact that the heating of local areas by a laser beam causes the material to bulge, swell or ablate resulting from hydrogen evolution at elevated temperatures (see "Optical Recording in Hydrogenated Semiconductors" by M. A. Bosch, Applied Physics Letters, Vol. 40, Jan. 1, 1981, pages 8-10).
Further, as shown in my U.S. Pat. No. 3,673,594, it is known that the magnetization of a material may be altered imagewise by the imagewise application of heat. In this patent, there is disclosed a process in which a zinc oxide layer is used to control the heat pattern generated by a radio-frequency field, the heat pattern corresponding to areas of the zinc oxide layer rendered conductive using xerographic techniques. Also, the patent discloses that a heat-sensitive material could be exposed to the pattern of heat generated by the zinc oxide layer resulting in an imagewise, viewable color change.